without the proprietary oscilloquartz configuration manager software you wouldn't be able to talk to the ocxo anyway. the protocol does not appear to be documented. nor does the software appear to be available anymore.
I recently got in one of the Oscilloquartz Star-4 GPSDOs off of Ebay:
http://www.ebay.com/itm/10Mhz-GPSDO-OSCILLOQUARTZ-OSA-OEM-GPS-GPSDO-10MHz-1PPS-STAR-GPS-Clock-/262675973538?hash=item3d28b545a2:g:sbYAAOSwh2xYAjrpThe serial port output on the unit is a NMEA output stream from the Ublox receiver. I don't think it has a serial input to the GPS.
The GPSDO board is mated to a well built board with a DC-DC converter and RS-232 interface. The 26-pin connector to the GPSDO is broken out to through-hole pads. On the connector is "management interface" serial link. The TX and RX management interface pins (3.3V, 9600 baud serial) are further broken out to some more pads. On the 26-pin connector pin 5A is serial data to the GPSDO, 5B is data from the GPSDO.
I got hold of some documentation for the Star-4 (still checking to see if I can share it).
I connected a RS-232 level converter to those pins and now have Lady Heather talking to it.
The control language lets you adjust the GPSDO time constant, satellite elevation mask, cable delay, enter/exit holdover, warm/cold start. You can monitor device status, alarms, satellite constellation, time/date/position, temperature. There are no messages that indicate things like the PPS time error / oscillator frequency / GPSDO performance.
The device saves the settings/configuration in EEPROM, but always does a 4-hour self-survey on power-up. It takes 10-15 minutes for the device to warm up and the GPSDO PLL to lock.
The next version of Lady Heather (with New and Improved Documentation (tm)) should be out in a couple of week...